Installation manual
Basictheory
Bymeansofamediumtiltangle(B)youwillmostlikelybeable
topickupscatteredshorschoolsifthesearelocatedatsome
distanceabovethebottom.Theupperschoolintheillustration
willappearonthesonarpicturebeforethebottomecho,whilethe
lowerschoolwilleasilybedisguisedbythebottomechoes.Once
againyoucanactivatetheRCGfunctiontoimprovethereading.
Noiseandreverberation
Everytimeyouusethesonarthequalityofyoursearch
operationswilldependonnumerouserrorsourcescausedbythe
naturalenvironmentandphysicalpropertiesofyourvessel.We
distinguishbetweenthetwotermsnoiseandreverberation.
•Noiseisgeneratedbythevessel:engine,propellers,winches,
refrigeratingplantsetc.
•Reverberationiscausedbynaturalconditionsinthesea:
temperature,salinity,seastateandbottomconditions.
Themostcommoncauseofacousticnoiseisthepropellerand
thecavitationcausedbyitsrotation.Othertypicalnoisesources
onboardyourvesselsarewinches,refrigeratingplants,power
generators,pumpsandcranes.Ifyouexperienceproblemsyou
thinkarecausedbynoise,trytondoutwhichsystemthatcauses
thenoise,andcontactyourdealerforadvice.
Cavitation
Asthepropellerbladesmovethroughthewater,lowpressure
areasareformedasthewateracceleratesaroundandmovespast
theblades.Thefasterthebladesmove,thelowerthepressure
arounditwillbecome.Asitreachesvapourpressure,thewater
vaporizesandformssmallbubblesofgas.Thisiscavitation.
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